1. Field of the Invention
The invention relates generally to arc lamp based systems, and specifically to the low electromagnetic radiation and low power loss interfacing of power supply systems with xenon arc lamps.
2. Description of the Prior Art
Short arc lamps provide intense point sources of light that allow light collection in reflectors for applications in medical endoscopes, instrumentation and video projection. Also, short arc lamps are used in industrial endoscopes, for example in the inspection of jet engine interiors. More recent applications have been in color television receiver projection systems.
A typical short arc lamp comprises an anode and a sharp-tipped cathode positioned along the longitudinal axis of a cylindrical, sealed concave chamber that contains xenon gas pressurized to several atmospheres. U.S. Pat. No. 5,721,465, issued Feb. 24, 1998, to Roy D. Roberts, describes such a typical short-arc lamp. A typical xenon arc lamp, such as the CERMAX marketed by EGG/ILC Technology (Sunnyvale, Calif.) has a two-legged strut system that holds the cathode electrode concentric to the lamp""s axis and in opposition to the anode.
Voltages as high as thirty kilovolts are needed to xe2x80x9cignitexe2x80x9d or start a xenon arc lamp. Once current starts to flow, the voltage can be reduced and the current regulated to safe limits. The arc lamps usually start on a first attempt by the igniter, but if that fails several more pulses of high voltage can be issued.
The pulsed nature of the voltages, the high voltages involved, and the current delivered to the arc lamp can all combine to generate strong electromagnetic interference (EMI). Significant impedances can also exist in the wiring that connects the power supply to the arc lamp, and these can dissipate substantial power. In some cases, poor coupling can prevent igniting the lamp on the first strike of the igniter.
It is therefore an object of the present invention to provide an efficient interface between a power supply and a xenon arc lamp.
Briefly, an arc lamp system embodiment of the present invention comprises a power supply coupled to a xenon arc lamp through an interface constructed on a heavy printed circuit board. Such plugs directly into an igniter printed circuit board. In turn, a xenon arc lamp module with heatsinks plugs directly onto banana plugs bolted on the interface printed circuit board. Copper traces buried on inner layers of the interface printed circuit board are very wide and heavy, and kept as short as possible.
An advantage of the present invention is that a xenon arc lamp system is provided with an interface that improves EMI and lamp operation.
These and other objects and advantages of the present invention will no doubt become obvious to those of ordinary skill in the art after having read the following detailed description of the preferred embodiment which is illustrated in the drawing figures.